I have made several searches across many boards but failed at finding a solution for my problem yet, even though it's been reported by some.

My phone was working fine for about a month, I was using the mass-storage technique without a problem until it stopped working one day.

Now, when I plug in my phone by usb to any computer, the connection screen will not come up, the battery charging icon sometimes fails to appear as well and I can hear the computer detecting a new device but it will not recognize it.

I did a hard reset on the phone, which ended up in 2.1 instead of the 2.2 i had, and the problem persists.

I have tried everything, from usb debugging mode to uninstalling/reinstalling drivers, even tried with my friend's cable and it does the same thing...I am very frustrated!

no, even though I have never used Kies (I prefer mass-storage liberty), I have installed Kies while troubleshooting and there is no detection whatsoever (I guess it would have worked before, back when it was working in mass-storage)
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user2655Feb 2 '11 at 4:57

Have you tried other data cables? Have you tried that cable with other devices?
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MattFeb 2 '11 at 9:38

yes as stated, i have tried with my friend's cable, which he was using just before, and it did the same thing
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user2655Feb 2 '11 at 20:35

actually, Ive had exactly the same problem, using vista. Initially when you download Kies and then install the drivers, it works for a while in the pc mode. kies just won't detect the phone, but another window comes up which asks you to either scan your drives or do nothing. I have not bothered resetting the phone back to factory settings. Im now going to try on another computer.
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user3123Feb 24 '11 at 22:41

It is not a driver problem because everything was working fine on my home and work computer until the problem occured, now it wouldnt work on neither of them. I have tried my friend's cable, the one he is using for his Android phone and which is confirmed to work. I guess I'll have to try calling Samsung. Scary.
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user2655Feb 2 '11 at 12:56

On the cell phone, dial the following number: *#7284# Once the last
# is hit, the PhoneUtil application is launched. Choose USB -> Modem and then USB -> PDA mode. The good mode should be PDA. Even if the
mode is PDA, switch to Modem and then back to PDA.